FabricPool/Inactive Data Reporting

tyrone_owen_1

Hi,

I'm looking into FabricPool for a supported FAS platform. The intention is to use the maximum cooling threshold of 183 days. Before I go down the route of enabling FabricPool, I want to run an analysis on the data to establish how much data qualifies as cold in relation to the 183 day cooling period. The documentation says:

• For an aggregate that is not used for FabricPool, inactive data reporting uses the tiering policy to decide how much data to report as cold.

  • For the none tiering policy, 31 days is used.

  • For the snapshot-only and auto, inactive data reporting uses tiering-minimum-cooling-days.

• For the ALL policy, inactive data reporting assumes the data will tier within a day.

             Until the period is reached, the output shows “-” for the amount of inactive data instead of a value.

Am I really going to have to wait 183 days before I can establish how much data qualifies as cold?

Thanks

Ontapforrum

It's not a dumb question at all (who cares). I find it interesting and tough to answer.

I am just trying to give some perspective to your query. Hopefully, experts will pitch in. You are anyway more than welcome to raise a ticket and put this question through. You can even put this question to your NetApp Account manager, and he will manage the reply for you.

My comments: Since data tiering is done at the "block level", a data block is considered cold after it hasn’t been accessed for a certain period of time, which is defined by the tiering policy’s minimum-cooling-days attribute. It doesn't care about the file, so I am guessing it is not going to tell you how old the file is based on the file's 'access/modify' time. Also, there is no visibility as which data type is cold. It is simply going to tell you the percentage of blocks that are cold. I believe once the scan is completed, it is just going to tell you how much '%' or 'mb/gb/tb' is cold, now whether it will report this after the configured cooling period has passed (irrespective of how old the files are) is something I am also unsure, but you can reach out to the channels I suggested.

However, if I read these lines from the following pdf, it clearly seconds what you have already stated.

https://docs.netapp.com/us-en/cloud-manager-tiering/faq-cloud-tiering.html

"IDR starts showing information after the configured cooling period has passed. Using ONTAP 9.7 and earlier, IDR had a non-adjustable cooling period of 31 days. Starting with ONTAP 9.8, the IDR cooling-period can be configured up to 183 days".

Kb for reference:
https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/How_does_the_FabricPool_inactive_data_reporting_work